The Fabrication For A New Kind Of Vapor Chamber And The Study Of Visualization Experiment

Phase change heat transfer components such as heat pipe,vapor chamber has been used widely in the field of electronic device cooling. Using the phase transition process of working medium, through the absorption and release of latent heat, vapor chamber achieves the goal of highly-efficient heat transfer performance. It can effectively solve the hot spots problem in high heat flux power device.How to make the smaller and thinner vapor chamber with higher heat transfer limit have important significance for electronic device cooling field. The development of the vapor chamber is reviewed in detail. On the basis of this, different forms of vapor chamber: Grooved and copper foam vapor chamber, are designed and produced The processing technology of vapor chamber is studied.The performance tests and the visualization experiment are also carried out.Firstly, the performance testing platform is established for the vapor chamber. The silver copper solder is applied to sinter both plates and filling tube of vapor chamber by vacuum brazing furnace.Using electronic filling system, water filling and vacuum pumping process are successfully completed.After spot welding method, the vapor chamber is fabricated. Further, the vapor chamber for the visualization are also designed and manufacturedThrough test, it is found that the overall performance of the foam copper wicks better than that groove wicks.The axial thermal resistance we manufactured are similar to the vapor chamber which was bought. In the before failure, the thermal resistance of vapor chamber can be reach to 0.2K/W.It is found that there is no attenuation failure phenomenon through two tests in different time.From the tests, we can see the rise of temperature of the groove vapor chamber is faster than the foam copper vapor chamber,and the startup time is about 3-5 mintute.lastly,we observing its internal working condition. Through observation, It is found that when filling amount is 30% for the first time,It is found no pool boiling phenomenon, but we can observe the phenomenon of drying up from the wicks center to periphery.The evaporation model is liquid membrane evaporation. Change the charging rate to 100%,and the heat flux density of less than 11W/cm2, it is found no apparent air bubbles, namely no pool boiling phenomenon, the evaporation model is liquid membrane evaporation too. And when continue increase heat flux density, we can see the pool boiling phenomena. In the porosity wicks, we can observe the pulsation phenomenon.This shows that under low charging rate and low heating power, its internal state mainly keep liquid membrane evaporation, not as we usually think of that pool boiling phenomenon; When reaches a certain liquid rate and a certain heating power, pool boiling phenomenon can only be seen.